Inflatable, collapsible, military pontoon bridge



* July`15, 1.947. u J, ,1 GEARQN 2,423,832

INFLATABLE, GOLLAPSIBLE, MILITARY PONTOON BRIDGE Filed DBG. 21. 1942 2Shee'iS-Sheet 2 Patented July 15.9 1947 INFLATABLE; COLLAPSIBLE,MILITARY PONTOON BRIDGE i J ames J. Gearon, Chicago, Ill.

Application December 21, 1942, Serial No. 469,715

Cl. 11d-0.5)`

Claims.

My invention relates to an improvedk pontoon bridge which is especiallyadapted for military and similar emergency uses. To this end I havedevised a novel pontoon bridge which is characterized by its ability tobe readily assembled for use, and which may be quickly knocked down intoa compact form for its transportation or storage in a limited space.These are essential advantages gained when this bridge is used formoving military forces across a body of water. Furthermore, theappurtenances andthe pontoons are equally capable of ready assembly inthe form of a dependable raft without the employment of extraneousappliances other than those which are employed for the bridge assembly.

Another feature of my improvements resides in the provision of a pontoonwhich comprises a body of predetermined and denite shape when it is ineither an inilated or a collapsed condition, which is of importancesince the required space for storage or transportation may be readilycalculated or estimated in advance of the actual work of disassemblingthe bridge and collapsing the pontoons. The bridge structure ischaracterized by the relatively small period of time which is requiredto assemble it for service or to knock down the structure when notneeded.

One of the objects of my invention is to utilize a novel constructionand improve the efliciency and operation of a bridge or raft of the typecontemplated herein.

Another object of my invention is to .provide several inner tubes or aircompartments to overcome damages caused by leaks or punctures.

Another object of my improvements resides in the provision of a pontoonbridge new indesign and which is adapted to perform its functions in anefficient manner.

A further object or aim of the present invention is toprovide a pontoonbridge which is made up of sturdy and dependable parts which are capableof withstanding the speedy action and severe usage which is demanded inmodern military service.

The novel improvementswhich I have disclosed herein are of compactarrangement; they are ex'- ceedingly dependable in operation; and thestructure is economical to produce in that it may be readily made fromcommercially available materials.

The above-mentioned as well as other objects, aims, and advantages of myimprovements will be obvious to persons who are skilled in the art afterthe construction and operation of my pontoon bridge is understood fromthe within description. I prefer to practice my invention and toaccomplish the objects thereof substantially in the manner hereinafterdescribed, and as more particularly pointed out in the appended claims.For a better understanding of these improvements, reference is now madeto the, accompanying drawings which form a part of this specica- In thedrawings:

Figure 1 is a top plan of a portion of a bridge or raft embodying myinvention and showing several inated pontoons.

Figure 2 is an edge view in elevation looking at the ends of thepontoons shown in Figure 1.

Figure 3 is a longitudinal side view of one of the pontoons as itappears when inilated.

Figure 4 is a vertical end'view in elevation of two pontoons showing anend brace therefor.

Figure 5 is a top plan of two pontoons showing the means for aligningthe same.

Figure 6 is a top plan of the ends of two pontoons in juxtaposition orclose assembly for use as a raft.

Figure 7 is a diagrammatic view of an end of a pontoon in a collapsed ordeflated condition..

Figure 8 is a top plan of the novel hook assembly used as an accessoryfor assembling my pontoon bridge structure.

Figure 9 is a side elevation of the hook shown in Figure 8. I

Figure 10 is a sectional view in a transverse plane to illustrate themanner of using the hook disclosed in Figures 8 and 9.

Figure 11 is a. diagram which shows several superposed bridge platesassembled with several hooks such as shown in Figures 8 and 9 for thepurpose of building plates up to different levels.

I1; will be understood that the drawings are of a more or less schematiccharacter, and that they disclose a typical or preferred embodiment ofmy invention and the manner in which it may be assembled. In thesedrawings, the same reference characters are used for the purpose ofidentifying like parts wherever these parts may appear in the differentviews.

Briefly stated, my pontoon bridge or raft comprises a plurality ofinflatable buoyant floats having reinforcing angle-metal frameworks attheir tops and provided with laterally anged side members which areutilized for connecting adjacent floats to each other in spacedrelation. Specially devised hook members are employed for connecting theiloats, and locking members are provided for connecting end to endarranged iloats. In order to support the roadway or platform,angle-metal stringers are mounted in a novel manner Von the reinforcingframes. All of the foregoing will now be described in detail inconnection with the drawings. J

In view of the fact that the floats or pontoon units are all of the sameconstruction, only a single unit will be described in order to avoidconfusing terminology. Each float or pontoon comprises a hollow envelopeor outer casing I which is preferably constructed of woven fabric suchas a heavy water-proof canvas, and when it is inflated under a normal orlow pressure it has a cross-sectional shape such as diagrammaticallyshown in Figure 2 which is substantially semicylindrical with anapproximately ilat top surface. This fabric envelope surrounds anelastic or expansible air tube 2 that may be of rubber or similarmaterial that is adapted to be inflated through a suitable valve 3 bymeans of a compression or similar pump. The upper portions of the endwalls of the envelope or casing have horizontal angle metal strips 4secured to them by rivets so that the lateral flange of these stripsproject outwardly from the end wall as seen in Figure 3. The sidemargins of the top wall of the fabric pontoon envelope havelongitudinally disposed angle metal strips 5 secured to them by rivetsand the upright flanges of these strips are spaced inwardly from themargins of the float as will be seen in Figure 2. The end strips 4 andside strips 5 constitute a rectangular framework surrounding andattached to the inflatable envelop I. This framework, being of a rigidcharacter, will tend to maintain the rectangular top wall of the envelopin a stretched and taut condition thereby holding down to a minimum thetendency of the top wall to bulge upwardly when desirably inflated. Eventhough there may be y some upward bulging of this taut top region of theenvelop when inflated, this'is not serious enough to interfere with theoperation of the pontoon float because of the overall weight of thestringers, platform members, and roadway which is supported by rails 5is ample to maintain proper assembly of the bridge components. The anglemetal strips 4 and 5 provide a definite and efficient reinforcement forthe upper portion of the pontoon to assist in maintaining the topthereof in rectangular outline. The upright flanges of the angle strips5 are adapted to support the stringers 6. These stringers 6 arepreferably inverted channel beams which are disposed with flat webuppermost and have notches I made in the lower portions of their langes,to rest upon and provide seats for the upright flanges of the l anglestrips 5 in the manner shown in Figures 2 and 3. The roadway orplatform, which usually consists of heavy planking, is laid across thesestringers in the customary manner.l This planking, however, is not shownin'the drawing as it forms no portion of my invention.

Near the upper portions of the semi-cylindrical or bottom wall of 'thefabric pontoon envelope there are angle metal strips 8 which are rivetedto said wall at locations in a horiozntal plane below the outwardlyprojecting flanges of the end angle strips 4. These angle strips 8 havetheir flanges projecting outwardly and when the pontoon is beingcollapsed or deflated they assume the positions shown in Figure 7. Theseangle strips 8 'further assist in reinforcing and providing rigidity tothe upper portions of the pontoon, and as shown in Figure 7 they do notinterfere with the deilating of the fabric envelope but on the contraryvthey assist in the collapsing of it into a predetermined shape havingdefinite dimensions.

The metal framework of each pontoon is spaced in a pattern designed todistribute the weight imposed on the top surface of the pontoon body sothat the maximum amount of balance and buoyancy is achieved. It will beappreciated the pontoon envelop need not be inflated tightly to itsfullest capacity to accomplish the desired buoyancy effect thereof, andunder such condition the walls of the envelop will retain theirapproximate normal shapes so that if there is any bulging of said wallsit would be more or less incidental and would be so slight as to'behardly noticeable. The envelop will thus tend to retain its generallysemicylindrical shape the top of which is restrained in its rectangularoutline by means of the angle metal frame members extendinglongitudinally and transversely around the top. The drawings, being of adiagrammatic or schematic character as previously stated, do not showbulged walls as it is apparent such characteristic would probably not bepresent except upon the inflation of the envelop with extremely highpressure.

Under ordinary conditions, the bridge may be assembled in the mannerabove described and as shown in Figures 1, 2, and 3, and theconstituents of the bridge will be retained securely in assembly due tothe fact that the stringere 6 which support the roadway planking areinterlocked by means of the notches 'I with the flanges of the anglestrips 5. It may be desired, however, to more rigidly connect theadjacent portions of the pontoons to prevent movement of one pontoonwith respect to the next pontoon, and one type of connecting means isshown in Figure 4 wherein S- shaped hooks 9 are engaged in holes made inthe angle strips 8 and in an intermediate tie-brace These hooks may beplaced between both ends of two of the pontoons to hold said pontoons inproper position and next to each other. Another form of connectionbetween adjacent pontoons is shown in Figure 5, which structure consistsof a rectangular plate II having a plurality of pulleys I2 mountedthereon with their axes vertically disposed. The cables I3 pass aroundthese pulleys and have their end portions connected to the anglev strips8. As shown in Figure 5 one end of each cable is provided with a loop I4which extends through an aperture in the angle strip and the other endof this cable is provided with a turn-buckle I5 for tightening the cablewith its ends fastened and its intermediate portions. running around oneof the pulleys. Also short 'cables I6 may similarly be connected attheir ends to the angle strip pieces 8 with their intermediate portionsrunning around the pulleys. In this arrangement the proper alignment anddispositionof the adjacent pontoons may be effectively adjusted andthe'pontoons will-thereafter be maintained in theirproper spacing fromeach other.

In Figure 6 there is shown'a pair of pontoons disposed closelyytogether, to provide a raft, and they are locked together by means ofthe novel spring hooks shown in Figures 8, 9, and 10, to be laterdescribed. In this structure the stringers 6 are provided with spacedbearing lugs I'I for journaling the trunnions of suitable clampingmembers I8 which are mounted thereon for hinging movement so that theywillextend over and other.

for an anchor which maybe used to stabilize the bridge and to preventits displacement by the current of the river which has been bridged.

As shown in Figure 6, the free ends of the hinged members I8 areprovided with holes or apertures I8a which are preferably shaped in theform of a figure-8 or two overlapped circles. Spring hooks such as shownin detail in Figures 8, 9, and 10 are adapted for cooperation with theapertures I8a for securing adjacent floats to each YAlthough thefigure-8 apertures are shown on the hinged members I8 it will beunderstood that similarly shaped apertures may be proximate faces of thebody members kare ta# pered outwardly as contemplated in Figure 8 toincrease yieldability since their mid-portions are secured together byrivets or otherwise. The lugs I4a and I5a are of semi-circularcross-section so that two side by side lugs form a circle and they areadapted to be separated after insertion in the apertures I8a to seat inthe opposite portions of the flgure-8 shape of said apertures. Thisseparation of the lugs is performed by means of tapered wedges I6depending from the outer free ends ofthe spring arms I'I which aremounted for swinging movement upon a pivot pin I8 that projects from themid-portion of the body members I4 and I5. Spring coils I9 are formed inthe arms I1 intermediate the pivot pin I8 and the outer ends of saidarms, and the internal diameters of said coils are sufficient to permitinsertion tive use of the fastening devices, a proper alinement may besecured by building up to a. proper height on the low frame withsuitable nested hollow fillers X or other means as shown in Fig. I I s0that the lugs Ila and I5al of the tie-clamps may be inserted into thecoaxial bores of these llers.

While I have describedvmy invention in detail in its present preferredform or embodiment, it will be obvious to those skilledin the art, afterunderstanding my improvements, that various changes and modificationsmay be made therein without departing from the spirit or scope there of.I intend in the appended claims to cover all such changes andmodifications.

What I claim is:

l. A float for pontoon bridges, rafts, and the like, comprising. aninflatable envelope having a normally flat rectangular surface regionand a region normally arcuate in cross-section, said envelope beingdisposed with its flat surface uppermost; a combinedenvelope-reinforcing and platform supporting frame secured to the upperportion of said envelope and having said flat surface region securedtaut thereto to restrict upward bulging thereof; and longitudinalmembers extending along the sides of said envelope, said longitudinalmembers adapted for cooperation with devices. for connecting the floatto an adjacent float.

2. A float for pontoon bridges, rafts, and the like, comprising aninflatable envelope having a i normally flat rectangular surface regionand a therethrough of the prongs of a double-claw bar whereby the armsmay be flexed upwardly and swung laterally to dispose thev wedges I6 atthe outer meeting portions of the spring body members I4 and I5 so thatsaid wedges may be forced in between them to thereby separate or spreadthe adjacent pair of lugs I4a and I5a to force the latter in the outerportions of the apertures I8a. f

This locking position of the parts'just described is illustratedin'detail in Figure 10..

When the bridge has been dismantled with the parts disassembled, theinflation valves are opened to exhaust the air from the pontoons therebydeflating the envelops which will then.l collapse 'so that thesemi-cylindrical wall of each will be snug against the flat top wall inthe manner shown by means of the diagram in Figure 7. In this collapsedcondition, the longitudinal angles 8 along opposite sides of the envelopwill assume the relative positions in Figure '7 wherein they are shownas being adjacent the end edges of the end strips or angles 4 and withtheir normally outwardly disposed flanges pointing upward in a verticaldirection. Figure 11 shows a number of bridge plates built up and heldtogether by the improved spring fastening hooks, thus illustrating howthe fastening device may be used either on top of two plate sections oron. the bottom of them thus holding the plates together in closeformation for assembling different parts of the structure.

When the frames on adjacent floats do not aline in a level horizontalplane to permit effecregion normally arcuate in cross-sectionI saidenvelope being disposed with its flat surface uppermost; an inflatableelastic air compartment within said envelope; a combinedenvelope-reinforcing and platform supporting'frame secured to the upperportion of said envelope and having said fiat surface region securedtaut thereto to restrict upward bulging thereof; and longitudinalmembers extending along the sides of said envelope,

said longitudinal members adapted for cooperation With devices forconnecting the float to an adjacent float.

3. A float for pontoon bridges, rafts, and the like, comprising aninflatable fabric body having a normally flat rectangular surface regionand a region normally arcuate in cross section, said fabric body beingdisposed with its flat surface uppermost; a combined fabricbody-reinforcing and platform supporting frame secured to the upperportion of said fabric body and having said fiat surface region securedtaut thereto to restrict upward bulging thereof; clamp plates hingedlymounted cnsaid frame; means for operatively connecting a clamp plate toa corresponding plate on another float; and longitudinal membersextending along the sides of said fabric body, said longitudinal membersadapted for cooperation With devices for `connecting the float to anadnecting a longitudinal member of one float to they longitudinal memberof an adjacent float; and

7 channel stringers mounted upon the supporting frames of a plurality'offloats.

5. Inapontoon bridge, a. plurality of floats each comprising aninflatable envelope having a, normally flat rectangular surfaceregionand a region normally arcuate in cross-section, said envelopebeing disposed with its flat surface uppermost; and an infiatablecollapsible rubber body within said envelope; combinedenvelope-reinforcing and platform supporting frames secured to the upperportions of said envelopes and having said flat surface region securedtaut thereto to restrict upward bulging thereof; lateral andlongitudinal members extending along the sides and ends of saidenvelopes; devices connecting a longitudinal member of one float tothelongitudinal member of an adjacent float; and channel stringeremountedupon the supporting frames of a D111- rality of floats.

6. In a pontoon bridge, a plurality of floats each comprising aninflatable fabric body having a normally iiat rectangular surface regionand a region normally arcuate in cross-section, said fabric body beingdisposed with its flat surface uppermost; combined fabricbody-reinforcing and platform supporting frames secured to the upperportions of each fabric body and having said flat surface region securedtaut thereto to restrict upward bulging thereof; longitudinal membersextending along the sides of said fabric bodies; hingedly mounted clampplates mounted on said frame; devices adapted for interlockingengagement with opposing clamp plates; devices connecting a longitudinalmember of one float to the longitudinal member of an adjacent float; andstringers mounted upon the supporting frames of a pluralityy of floats.

'7. A collapsible float for pontoon bridges, rafts, and the like,comprising an inflatable fabric body having a normally flat rectangularsurface l region and a region normally arcuate in crosssection, saidbody being disposed with its ilat surface uppermost; longitudinal andtransverse angle-metal strips providing a rectangular reinforcing framesecured to the top of said fabric body and having said flat surfaceregion secured taut thereto to restrict upward bulging thereof; andlongitudinal side members extending along opposite walls of said fabricbody below the plane of said frame and adapted for connection with theside member of an adjacent float, the said frame and side membersdisposed to facilitate collapsing of the float into a fiat condition forstorage in a constricted space.

8. A pontoon bridge comprising a plurality of inflatable float bodieseach having a normally fiat rectangular region and a region normallyarcuate in cross-section, said bodies when in use being disposed withthe flat regions uppermost; reinforcing angle-metal strips secured to fthe upper portions of saidoats and provided with fastening apertures.and being arrangedvto normally hold the at regions. taut to restrictupward bulging thereof; stringers supported by certain of said vangle-metal strips above said floats;v and devices connecting adjacentfloats, said devices each consisting of yeldable arms having lateralsde-by-side hooks at their ends for entry into the aforesaid apertures;and wedges adapted to engage and separate said arms to urge said hooksinto firm engagement with said apertures.

9. A collapsible float for pontoon bridges, rafts, and the like,comprising an inflatable fabric body having a normally flat rectangularregion and a region normally arcuate in cross-section, said oat when inuse being disposed with its flat surface uppermost; longitudinal andtransverse angle-metal strips providing a rectangular reinforcing framesecuredto the top of said fabric body and having said flat surfaceregion secured taut thereto to restrict upward bulging thereof;longitudinal side members extending along opposite walls of said fabricbody below the plane of said frame; relatively movable clamp armsadapted for engagement with said side members for connecting adjacentfloats; and wedging devices for causing relative movement of said clamparms.

10. A pontoon bridge comprising a plurality of inflatable float bodies;reinforcing frames secured to the upper portions of said bodies andprovided with apertures said frames being adapted to hold taut the upperregions of said iioats thereby to restrict upward bulging thereof; anddevices connecting adjacent floats, said devices comprising oppositelydisposed yieldable arms; laterally disposed side-by-side hooks atopposite ends of said arms for entry into the aforesaid apertures; andWedges adapted to engage and separate said arms to urge said hooks intoflrm engagement with said apertures; a spring bar pivoted intermediateits ends on said yieldable arms; and laterally disposed wedges at theends of said spring bar, said wedges adapted to be inserted between saidarms to move the said hooks away from each other and into rigidengagement with the respective apertures.

JAMES J. GEARON.

REFERENCES CITED The following references are of record in the file ofvthis patent:

UNITD STATES PATENTS Number Name Date 1,723,213 Smith Aug. 6, 1929522,348 Martini July 3, 1894 1,470,459 Lonsinger Oct. 9, 1923 1,279,097Fredeen Sept. 17, 1918 2,085,156 Hill June 29, 1937 659,883 Webster Oct.16, 1900 1,093,987 Gleason Apr. 21, 191,4 1,671,642 Hopkinson May 29,1928

